1. LOW GRADE WHU POTENTIAL- TEXTILE SECTOR
Partnership to Advance Clean Energy-Deployment (PACE-D) Technical Assistance Program
R Rajmohan
12-Aug-14

2. CONTENTS
Process Flow
Sources of Low Grade Waste Heat
Overall Potential
WHU Solutions
Case Studies

3. Textile Processing : Illustrative for Cotton Prints
Utilities
Grey Fabric
Singeing
Washing
Mercerizing
Kier Boiling
Scouring/ Bleaching
Dyeing
Stenter Dyeing
Printing
Steam Aging
Resin Finishing
Felt Finishing
Inspection
Boiler
Thermopac
Air compressors
Source: Cluster Manual Pali Textile Cluster; BEE

4. Textile Processing : Pali Textile cluster- Quick overview
Sl No
Item
Target Efficiency 1
Sources of Energy
Electricity from Grid & Pet Coke 2
Energy Use pattern – Pet Coke
5 to 7 TPD (Power process)
1 to 1.5 TPD (Small Units) 3
Energy Use pattern- Electricity
Power Process: 3000 kWh/Day
Only printing: kWh/Day 4
Specific energy consumption ( Processing of polyester & Printing)
Electricity: 1.2 kWh/Kg
Thermal: Kcals/Kg
Source: Cluster Manual Pali Textile Cluster; BEE

5. Sources of Waste Heat Drying Stente r Dyeing Jigger Singei ng
Condensate
Vapor
Hot effluent
Flue gas
None
Drying
Stente r
Dyeing
Jigger
Singei ng
Stretc hing
Water
Steam (LP) 3 bar
Thermic fluid
210 oC
Steam (MP) 5 bar
Steam (LP)
LPG flame
Fuel
Steam (LP) 3 bar
Boiler
Blow Down
Flue gas

6. Low Grade WH: Overall Potential
Effluents
Quantity: 3000 Kg/Cycle
Temperature: 70 Deg C
WHR potential: Kcals/Cycle
Jiggering & Swing Steam
Reject condensate: 120 Kg/Hr
Temperature: 70 Deg C
WHR potential: 6300 Kcals/Cycle
140 Deg C
Reject effluent: 5000 Kg/Hr
Temperature: 100 Deg C
WHR potential: Kcals/Cycle
120 Deg C
Reject Effluent: 123 Kg/Hr
Temperature: 100 Deg C
WHR potential: 1230 Kcals/Cycle
WHU- Overall potential
0.323 Kg of Fuel/Kg of Cloth
Annual fuel savings: 93 MT/Year
Cost savings: 11.2 Lac Rs/Year
Drying & Jiggering Steam
Reject Effluent: 200 Kg/Hr
Temperature: 70 Deg C
WHR potential: Kcals/Cycle
Drying & Jiggering water
Reject condensate: 3500 Kg/Hr
Temperature: 70 Deg C
WHR potential: Kcals/Cycle
Mill producing 37 Kg of cloth/Hr

7. Low Grade WHU Technologies: Waste heat recovery from Boiler Flue gases - Economizer
To Chimney
Feed water Pump
200 Deg.C
T1= 30 Deg.C
150 Deg.C
T2 = 50 Deg.C
Waste heat recovery device
Usually used in boilers to recover waste heat from flue gases.
Recovered heat is used to pre-heat feed water to boiler
Useful where water feeding to boiler is continuous

8. Low Grade WHU Technologies: Waste heat recovery from Boiler/Thermopac Flue gases – Air Preheater
APH
FD Fan
200 Deg.C
T1= 30 Deg.C
150 Deg.C
T2 = 80 Deg.C
Combustion air
Waste heat recovery device
Usually used in boilers/Furnaces to recover waste heat from flue gases.
Recovered heat is used to pre-heat combustion air to boiler/Furnace
Useful where Economizer exists already

9. Waste heat recovery device
Low Grade WHU Technologies: Waste heat recovery from Boiler Flue gases – Water Preheater (S&T heat exchanger)
Boiler
Flue
Gas
S& T
H E
To Chimney
Water Pump
Feed Water Tank
Feed water Pump
Waste heat recovery device
Usually used in boilers to recover waste heat from flue gases.
Recovered heat is used to pre-heat boiler feed water
Useful when the feed water flow to the boiler is not continuous

10. Low Grade WHU Technologies: Waste heat recovery from Boiler Flue gases – Water Preheater- Heat pipe heat exchanger
Waste heat recovery device
Usually used in boilers to recover waste heat from flue gases.
Recovered heat is used to pre-heat feed water to boiler
Useful to recover heat where Delta T is lower

11. Low Grade WHU Technologies: WHR from Boiler Blow Down – Flash Steam Recovery & Heat recovery from BD condensate
Flash steam recovery from Boiler blow down
Heat recovery from the condensate of the blow down
Recovered heat is used to pre-heat Boiler feed water/ other hot water requirements

12. Low Grade WHU Technologies: Condensate Recovery
Condensate recovery device
No mechanical pumping
Recovered condensate is used as boiler feed water
Savings of both water and heat

13. Low Grade WHU Technologies: Heat Recovery from Hot effluents
Waste heat recovery device
Used to recover heat from process effluents

14. Low Grade WHU Technologies: Heat Recovery from Hot Vapours
Hot vapors from sources like Stenters are the heat source
Used to either generate hot water or to heat the fresh air to the source equipments

15. CASE STUDY 1 : Waste heat recovery system in Boiler

16. CASE STUDY 2 : Waste heat recovery system in Thermopac

17. CASE STUDY 3 : Waste heat recovery –Boiler Blowdown

18. CASE STUDY 4 : Waste heat recovery- Jet Dyeing Machine

19. CASE STUDY 5 : PHE – Heat Recovery from Jet Dyeing Machine (Sameer Synthetics)
Temp. of water drained : 85oC
Proposal : Collect hot water and use for pre-heating cold water stream used for process

20. CASE STUDY 2: Cost Benefit Analysis
Number of Machines in Operation 9
Quantity of Water Drained/Batch/Machine
400 l
Number of batches/day/machine 10
Water temperature at outlet of machine
80oC
Expected temperature of effluent at outlet of PHE
38oC
Expected energy savings
1,512,000 kCal/day
Equivalent Fuel Savings
189 kg/day
Equivalent Cost Savings
6.8Lakh Rs/year
Investment
4 Lakh Rs
Simple Payback Period
7 Months